The economy class syndrome

Abstract

The "economy class syndrome" is a thromboembolic phenomenon affecting passengers after a long, longer than 5 hours, air travel. Its symptoms are usually manifested within 4 weeks of the flight and refiect reflect deep vein thrombosis, usually of the lower limbs, not rarely complicated by pulmonary embolism. In spite of its name it may occur in passengers travelling in business or first class or even by other means such as train or car and some authors suggest that the term "traveler's thrombosis" is more suitable to the phenomenon. Its incidence varies, between 3% and 7%, according to studies, mostly retrospective and, to a lesser extend and more recently, prospective and comparative. Among them the studies by Clerel and Gaillard, Ferrari, Machin, and Lapostolle should be mentioned, whereas in the LONFLIT studies the importance of coexisting risk factors in some travelers is investigated and the need for preventive measures is designated. The pathogenesis of the phenomenon is based on the consequences of prolonged immobilization, i.e. blood stasis in the veins and activation of coagulation as well as endothelial lesion of the vessels. To these are added the altered atmospheric pressure inside the aircraft, hypoxia, dehydration, turbulences, stress etc. The possibility of screening tests detecting pre-existing risk factors in some travelers is questioned. The preventive measures proposed include the responsibility of the airline carriers to inform the passengers and personal precautions such as frequent immobilisation during the flight, the use of compressive stockings or foot pump as well as, in case of additional risk factors (hypercoagulability, thrombophilia), the use of antithrombotic drugs such as aspirin or low molecular weight heparins.